U.S. patent number 11,409,230 [Application Number 17/379,094] was granted by the patent office on 2022-08-09 for developing cartridge including first and second cams connected by connection member and movable relative to casing.
This patent grant is currently assigned to BROTHER KOGYO KABUSHIKI KAISHA. The grantee listed for this patent is BROTHER KOGYO KABUSHIKI KAISHA. Invention is credited to Junichi Hashimoto, Yasushi Okabe.
United States Patent |
11,409,230 |
Hashimoto , et al. |
August 9, 2022 |
Developing cartridge including first and second cams connected by
connection member and movable relative to casing
Abstract
A developing cartridge includes: a casing; a developing roller
rotatable about an axis extending in a first direction; a first cam
positioned at one end portion of the casing; a second cam
positioned at another end portion of the casing; and a connection
member connecting the first cam and the second cam to each other.
The first cam is movable relative to the casing and the developing
roller in the first direction between a first position and a second
position, and the second cam is movable relative to the casing and
the developing roller in the first direction between a third
position and a fourth position. The second cam is movable from the
third position to the fourth position due to a tensile force of the
connection member in accordance with movement of the first cam from
the first position to the second position.
Inventors: |
Hashimoto; Junichi (Toyohashi,
JP), Okabe; Yasushi (Nagoya, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
BROTHER KOGYO KABUSHIKI KAISHA |
Nagoya |
N/A |
JP |
|
|
Assignee: |
BROTHER KOGYO KABUSHIKI KAISHA
(Nagoya, JP)
|
Family
ID: |
1000006482040 |
Appl.
No.: |
17/379,094 |
Filed: |
July 19, 2021 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20210341874 A1 |
Nov 4, 2021 |
|
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
PCT/JP2020/005466 |
Feb 13, 2020 |
|
|
|
|
Foreign Application Priority Data
|
|
|
|
|
Mar 28, 2019 [JP] |
|
|
JP2019-063305 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03G
21/1676 (20130101); G03G 21/1647 (20130101) |
Current International
Class: |
G03G
21/16 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
60-125865 |
|
Jul 1985 |
|
JP |
|
5-35078 |
|
Feb 1993 |
|
JP |
|
8-171324 |
|
Jul 1996 |
|
JP |
|
2001-22159 |
|
Jan 2001 |
|
JP |
|
2011-59510 |
|
Mar 2011 |
|
JP |
|
2013-125149 |
|
Jun 2013 |
|
JP |
|
2014-170254 |
|
Sep 2014 |
|
JP |
|
Other References
International Search Report issued in PCT/JP2020/005466 dated Mar.
17, 2020. cited by applicant.
|
Primary Examiner: Chen; Sophia S
Attorney, Agent or Firm: Merchant & Gould P.C.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This is a by-pass continuation application of International
Application No. PCT/JP2020/005466 filed Feb. 13, 2020 claiming
priority from Japanese Patent Application No. 2019-063305 filed
Mar. 28, 2019. The entire contents of the International Application
and the priority application are incorporated herein by reference.
Claims
What is claimed is:
1. A developing cartridge comprising: a casing configured to
accommodate developing agent therein, the casing including one end
portion and another end portion spaced apart from the one end
portion in a first direction; a developing roller rotatable about a
developing roller axis extending in the first direction; a first
cam positioned at the one end portion of the casing, the first cam
being movable relative to the casing and the developing roller in
the first direction between a first position and a second position,
the first cam in the second position being positioned closer to the
another end portion of the casing in the first direction than the
first cam in the first position is to the another end portion of
the casing; a second cam positioned at the another end portion of
the casing, the second cam being movable relative to the casing and
the developing roller in the first direction between a third
position and a fourth position, the second cam in the fourth
position being positioned closer to the another end portion of the
casing in the first direction than the second cam in the third
position is to the another end portion of the casing; and a
connection member connecting the first cam and the second cam to
each other, wherein the second cam is movable from the third
position to the fourth position due to a tensile force of the
connection member in accordance with movement of the first cam from
the first position to the second position.
2. The developing cartridge according to claim 1, wherein the first
cam has a first end and a second end, the second end being
positioned closer to the another end portion of the casing in the
first direction than the first end is to the another end portion of
the casing, wherein the second cam has a third end and a fourth
end, the fourth end being positioned closer to the another end
portion of the casing in the first direction than the third end is
to the another end portion of the casing, and wherein the
connection member connects the first end of the first cam and the
fourth end of the second cam to each other.
3. The developing cartridge according to claim 2, wherein the first
end of the first cam has a pressure contact surface for receiving a
pressing force, and wherein, when the pressure contact surface
receives the pressing force, the first cam moves from the first
position to the second position.
4. The developing cartridge according to claim 3, wherein the
developing cartridge is for use with a drum cartridge, the drum
cartridge being attachable to a main body portion of an image
forming apparatus in a state where the developing cartridge is
attached to the drum cartridge, the main body portion including a
drive shaft extending in the first direction, the drive shaft being
movable in the first direction between an advanced position and a
retracted position in response to receiving a driving force applied
from the main body portion, the drive shaft being configured to
press the pressure contact surface by the movement of the drive
shaft toward the advanced position which is a direction from the
one end portion to the another end portion of the casing in the
first direction.
5. The developing cartridge according to claim 1, wherein the
developing roller has an outer circumferential surface including
one end portion and another end portion in a second direction
crossing the first direction, the one end portion in the second
direction of the outer circumferential surface of the developing
roller being exposed to an outside of the casing, the another end
portion in the second direction of the outer circumferential
surface of the developing roller being positioned inside the
casing.
6. The developing cartridge according to claim 5, wherein the
casing has one outer surface and another outer surface, the one
outer surface being positioned at one end portion in the second
direction of the casing, the another outer surface being positioned
at another end portion in the second direction of the casing,
wherein the first cam and the second cam are positioned at the one
outer surface, and wherein the connection member has at least a
portion extending in the first direction along the another outer
surface.
7. The developing cartridge according to claim 6, wherein the
casing further has a groove positioned at the another outer surface
and extending in the first direction, and wherein the connection
member has at least a portion positioned within the groove.
8. The developing cartridge according to claim 6, wherein the
casing has a first guide groove and a second guide groove
positioned at the one outer surface, the first guide groove guiding
movement of the first cam between the first position and the second
position, the second guide groove guiding movement of the second
cam between the third position and the fourth position.
9. The developing cartridge according to claim 8, wherein the
casing includes a frame having a flat plate shape and positioned at
the one outer surface, the frame having the first guide groove and
the second guide groove.
10. The developing cartridge according to claim 8, wherein at least
one of the first cam and the second cam includes a retainer for
preventing the at least one of the first cam and the second cam
from disengaging from corresponding one of the first guide groove
and the second guide groove.
11. The developing cartridge according to claim 5, wherein the
casing has one outer surface and another outer surface, the one
outer surface being positioned at one end portion in the second
direction of the casing, the another outer surface being different
from the one outer surface, wherein the first cam and the second
cam are positioned at the one outer surface, and wherein the
connection member has at least a portion extending in the first
direction along the another outer surface.
12. The developing cartridge according to claim 5, wherein the
first cam has a first inclined surface inclined relative to the
first direction so as to be distant from the casing as extending
from the another end portion to the one end portion of the casing,
and wherein the second cam has a second inclined surface inclined
relative to the first direction so as to be distant from the casing
as extending from the another end portion to the one end portion of
the casing.
13. The developing cartridge according to claim 12, wherein the
first inclined surface gradually approaches the casing in the
second direction as extending from the one end portion to the
another end portion in the first direction of the casing, and
wherein the second inclined surface gradually approaches the casing
in the second direction as extending from the one end portion to
the another end portion in the first direction of the casing.
14. The developing cartridge according to claim 12, wherein the
developing cartridge is for use with a drum cartridge, the drum
cartridge has having a first contact surface and a second contact
surface, the drum cartridge being attachable to a main body portion
of an image forming apparatus in a state where the developing
cartridge is attached to the drum cartridge, and wherein, in the
state where the developing cartridge is attached to the drum
cartridge, the first contact surface is in contact with the first
inclined surface, and the second contact surface is in contact with
the second inclined surface.
15. The developing cartridge according to claim 14, wherein the
first contact surface is at least a portion of an outer
circumferential surface of a first cylinder centered on a first
rotational axis extending in a third direction crossing the first
direction, and wherein the second contact surface is a at least a
portion of an outer circumferential surface of a second cylinder
centered on a second rotational axis extending in the third
direction.
16. The developing cartridge according to claim 15, wherein the
first cylinder is rotatable about the first rotational axis, and
wherein the second cylinder is rotatable about the second
rotational axis.
17. The developing cartridge according to claim 5, wherein the
first cam is movable in the second direction together with the
casing and the developing roller, and wherein the second cam is
movable in the second direction together with the casing and the
developing roller.
18. The developing cartridge according to claim 5, wherein the
developing cartridge is for use with a drum cartridge including a
photosensitive drum, and wherein, in a state where the developing
cartridge is attached to the drum cartridge, the first cam is
movable in the second direction relative to the photosensitive drum
together with the casing and the developing roller, and the second
cam is movable in the second direction relative to the
photosensitive drum together with the casing and the developing
roller.
19. The developing cartridge according to claim 18, wherein, in the
state where the developing cartridge is attached to the drum
cartridge, the developing roller is in contact with the
photosensitive drum in the first position of the first cam and in
the third position of the second cam, and the developing roller is
separated from the photosensitive drum in the second position of
the first cam and at the fourth position of the second cam.
20. The developing cartridge according to claim 5, wherein the
casing has one end portion in a third direction crossing the first
direction and the second direction, and wherein the developing
roller is positioned at the one end portion in the third direction
of the casing.
21. The developing cartridge according to claim 20, wherein the
casing further has an outer surface positioned at another end
portion in the third direction of the casing, the developing
cartridge further comprising a handle configured to be gripped by a
user, the handle being positioned at the outer surface.
22. The developing cartridge according to claim 1, wherein the
connection member is a flexible member.
23. The developing cartridge according to claim 22, wherein the
connection member is one of a sheet-like member and a wire
member.
24. The developing cartridge according to claim 1, wherein the
connection member has a portion extending in the first direction
and another portion extending in a direction crossing the first
direction.
25. The developing cartridge according to claim 1, further
comprising an elastic member urging the second cam in a direction
from the fourth position toward the third position.
26. The developing cartridge according to claim 25, wherein the
elastic member is a spring.
27. The developing cartridge according to claim 26, wherein the
spring is a coil spring.
28. The developing cartridge according to claim 1, wherein the
connection member is made from resin.
Description
TECHNICAL FIELD
The present disclosure relates to a developing cartridge.
BACKGROUND
Conventionally, there has been known an electro-photographic type
image forming apparatus such as a laser printer and an LED printer.
The image forming apparatus includes a developing cartridge. The
developing cartridge includes a developing roller for supplying
developing agent. One conventional image forming apparatus is
described in a prior art, for example. The image forming apparatus
described in the prior art includes a drum cartridge including a
photosensitive drum. The developing cartridge is attachable to the
drum cartridge. Upon attachment of the developing cartridge to the
drum cartridge, the photosensitive drum and the developing roller
are brought into contact with each other.
SUMMARY
The image forming apparatus disclosed in the prior art is
switchable between a state where the developing roller and the
photosensitive drum are in contact with each other and a state
where the developing roller and the photosensitive drum are
separated from each other. In the image forming apparatus disclosed
in the prior art, components for moving the developing cartridge to
separate the developing roller from the photosensitive drum are
provided at each side of a drum unit. The components at each side
need to receive a driving force from a main body of the image
forming apparatus.
In view of the foregoing, it is an object of the present disclosure
to provide a developing cartridge capable of moving a developing
roller away from a photosensitive drum due to a driving force
applied to only one side without necessitating application of a
driving force to both sides.
In order to attain the above and other objects, according to one
aspect, the present disclosure provides a developing cartridge
including: a casing; a developing roller; a first cam; a second
cam; and a connection member. The casing is configured to
accommodate developing agent therein. The casing includes one end
portion and another end portion spaced apart from the one end
portion in a first direction. The developing roller is rotatable
about a developing roller axis extending in the first direction.
The first cam is positioned at the one end portion of the casing.
The first cam is movable relative to the casing and the developing
roller in the first direction between a first position and a second
position. The first cam in the second position is positioned closer
to the another end portion of the casing in the first direction
than the first cam in the first position is to the another end
portion of the casing. The second cam is positioned at the another
end portion of the casing. The second cam is movable relative to
the casing and the developing roller in the first direction between
a third position and a fourth position. The second cam in the
fourth position is positioned closer to the another end portion of
the casing in the first direction than the second cam in the third
position is to the another end portion of the casing. The
connection member connects the first cam and the second cam to each
other. The second cam is movable from the third position to the
fourth position due to a tensile force of the connection member in
accordance with movement of the first cam from the first position
to the second position.
BRIEF DESCRIPTION OF THE DRAWINGS
The particular features and advantages of the embodiment(s) as well
as other objects will become apparent from the following
description taken in connection with the accompanying drawings, in
which:
FIG. 1 is a schematic diagram of an image forming apparatus
including a developing cartridge according to one embodiment of the
present disclosure;
FIG. 2 is a view of a drum cartridge to which the developing
cartridge according to the embodiment is attached as viewed in a
third direction from another side toward the one side;
FIG. 3 is a perspective view of a first cylinder and a bearing that
supports the first cylinder of the drum cartridge;
FIG. 4 is a perspective view of a second cylinder and a bearing
that supports the second cylinder of the drum cartridge;
FIG. 5 is a perspective view of the developing cartridge according
to the embodiment;
FIG. 6 is another perspective view of the developing cartridge
according to the embodiment;
FIG. 7 is still another perspective view of the developing
cartridge according to the embodiment;
FIG. 8 is a perspective view of a first cam, a second cam, and a
connection member in the developing cartridge according to the
embodiment;
FIG. 9 is a perspective view of the developing cartridge according
to the embodiment in which the connection member has been
removed;
FIG. 10 is a view illustrating a portion in the vicinity of a
retainer of the first cam in the developing cartridge according to
the embodiment;
FIG. 11 is a view illustrating the developing cartridge according
to the embodiment and a photosensitive drum in the drum cartridge
in a contacting state of the image forming apparatus as viewed in a
first direction from another side toward one side;
FIG. 12 is a view illustrating the developing cartridge according
to the embodiment in the contacting state of the image forming
apparatus as viewed in the third direction from the other side
toward the one side;
FIG. 13 is a perspective view of the developing cartridge according
to the embodiment and the photosensitive drum in the drum cartridge
in the contacting state of the image forming apparatus;
FIG. 14 is a view illustrating the developing cartridge according
to the embodiment and the photosensitive drum in the drum cartridge
in a separated state of the image forming apparatus as viewed in
the first direction from the other side toward the one side;
FIG. 15 is a view illustrating the developing cartridge according
to the embodiment in the separated state of the image forming
apparatus as viewed in the third direction from the other side
toward the one side; and
FIG. 16 is a perspective view of the developing cartridge according
to the embodiment and the photosensitive drum in the drum cartridge
in the separated state of the image forming apparatus.
DETAILED DESCRIPTION
Hereinafter, one embodiment of the present disclosure will be
described while referring to the accompanying drawings.
In the following description, a direction in which a rotational
axis of a developing roller (a developing roller-axis) will be
referred to as "first direction". Here, an outer circumferential
surface of the developing roller includes a portion exposed to an
outside of a casing, and another portion positioned inside the
casing. A direction in which the portion of the circumferential
surface of the developing roller and the other portion of the
circumferential surface of the developing roller are arrayed will
be referred to as "second direction". The first direction and the
second direction cross each other. Preferably, the first direction
and the second direction are perpendicular to each other. Further,
a direction crossing both the first direction and the second
direction will be referred to as "third direction". Preferably, the
third direction is perpendicular to both the first direction and
the second direction.
<1. Overall Configuration of Image Forming Apparatus>
FIG. 1 is a schematic diagram of an image forming apparatus 100.
The image forming apparatus 100 is an electro-photographic type
printer such as a laser printer and an LED printer. As illustrated
in FIG. 1, the image forming apparatus 100 includes four developing
cartridges 1, a drum cartridge 2, and a main body portion 9.
<1-1. Overall Configuration of Main Body Portion>
Hereinafter, an overall configuration of the main body portion 9
will be described. The main body portion 9 includes a main frame
101, a transfer belt (not illustrated), and a controller 102.
The main frame 101 has a generally rectangular-parallelepiped
shape, and has an internal space. The drum cartridge 2 to which the
developing cartridges 1 are attached can be accommodated in the
internal space of the main frame 101. Further, four chargers (not
illustrated), four light sources (not illustrated), the transfer
belt, and the controller 102 are provided in the main frame
101.
The transfer belt is an endless belt for conveying printing sheets.
The transfer belt is positioned opposite to developing rollers 30
with respect to photosensitive drums 21 of the drum cartridge 2 in
a state where the drum cartridge 2 to which the developing
cartridges 1 are attached is positioned in the internal space of
the main frame 101. The transfer belt has an outer peripheral
surface capable of contacting outer circumferential surfaces of the
photosensitive drums 21.
The controller 102 includes a processor such as CPU, and a main
body memory. The main body memory is a storage medium from which
information is readable and to which information is writable. For
example, the main body memory is a flash ROM or an EEPROM. The
memory stores therein computer programs for controlling operations
performed in the image forming apparatus 100. The processor is
configured to execute various processing in accordance with the
computer programs stored in the memory. That is, the processor is
configured to execute various printing process and other processes
associated therewith to be performed in the image forming apparatus
100.
<1-2. Overall Configuration of Drum Cartridge>
Next, an overall configuration of the drum cartridge 2 will be
described. FIG. 2 is a view of the drum cartridge 2 to which the
developing cartridges 1 are attached as viewed in the third
direction from another side toward one side. As illustrated in
FIGS. 1 and 2, the drum cartridge 2 includes the four
photosensitive drums 21, and a frame 200.
Each of the four photosensitive drums 21 illustrated in FIG. 1 has
an outer circumferential surface having a cylindrical shape
centered on a drum axis, which is a rotational axis extending in
the first direction. The outer circumferential surface of each
photosensitive drum 21 is coated with photosensitive material. Each
of the photosensitive drums 21 is rotatable about its drum
axis.
The frame 200 is a frame that supports the four photosensitive
drums 21 such that the four photosensitive drums 21 are arranged to
be spaced from one another in the second direction. The frame 200
includes a pair of side frames 201 and 202 facing each other in the
first direction. The photosensitive drums 21 are rotatably
supported by the side frames 201 and 202.
<1-3. Overall Configurations of Developing Cartridges>
Hereinafter, overall configurations of the developing cartridges 1
will be described. FIGS. 5 to 7 are perspective views of the
developing cartridge 1.
As illustrated in FIGS. 1 and 2, the developing cartridges 1 are
attachable to and detachable from the frame 200 of the drum
cartridge 2. As illustrated in FIG. 5, each of the developing
cartridges 1 includes a casing 10 configured to accommodate
developing agent therein. The casing 10 includes a container 10A
and a lid 10B (an example of a frame). The container 10A has an
internal space. The lid 10B has a flat plate shape. The lid 10B is
positioned at one end portion in the second direction of the casing
10 to cover an opening formed at one end portion in the second
direction of the container 10A. Further, the lid 10B has a third
outer surface 13 (described later). In the meantime, the container
10A further has an opening portion 10C at one end portion in the
third direction thereof. The developing roller 30 (described later)
is positioned in the opening portion 10C.
The casing 10 has one end portion 91, and another end portion 92
spaced apart from the one end portion 91 in the first direction. A
first outer surface 11 is positioned at the one end portion 91 of
the casing 10, and a second outer surface 12 is positioned at the
other end portion 92 of the casing 10. That is, the first outer
surface 11 is positioned at one end portion in the first direction
of the casing 10, while the second outer surface 12 is positioned
at another end portion in the first direction of the casing 10. The
casing 10 further has the third outer surface 13 and a fourth outer
surface 14 (see FIG. 7) spaced apart from each other in the second
direction. The third outer surface 13 is positioned at one end
portion in the second direction of the casing 10. The fourth outer
surface 14 is positioned at another end portion in the second
direction of the casing 10.
The four developing cartridges 1 accommodate therein toners of
colors different from one another (for example, cyan, magenta,
yellow and black). However, the developing cartridges 1 may
accommodate therein toner of the same color.
Each of the developing cartridges 1 includes the developing roller
30 having a cylindrical shape. The developing roller 30 is
rotatable about a developing roller-axis which is a rotational axis
extending in the first direction. The developing roller 30 is
supported by the casing 10 so as to be rotatable about the
developing roller-axis.
The developing roller 30 includes a developing roller body 31 and a
developing roller shaft 32. The developing roller body 31 has a
hollow cylindrical shape and extends in the first direction. The
developing roller body 31 is made of material having elasticity
such as rubber. The developing roller shaft 32 is a solid
cylindrical member that penetrates the developing roller body 31 in
the first direction. The developing roller shaft 32 is made of
metal or electrically conductive resin.
The developing roller body 31 is fixed to the developing roller
shaft 32 so that relative rotation of the developing roller body 31
with respect to the developing roller shaft 32 is prevented. That
is, the developing roller body 31 is rotatable together with the
developing roller shaft 32 about the developing roller-axis. An
outer circumferential surface of the developing roller body 31
having one end portion in the second direction exposed to an
outside of the casing 10 through the opening portion 10C. Another
end portion in the second direction of the outer circumferential
surface of the developing roller body 31 is positioned inside the
casing 10.
A developing roller gear (not illustrated) is coupled to one end
portion in the first direction of the developing roller shaft 32.
The developing roller gear is positioned at the first outer surface
11. The developing roller gear is fixed to the developing roller
shaft 32 so that relative rotation between the developing roller
gear and the developing roller shaft 32 is prevented. Hence,
rotation of the developing roller gear causes rotation of the
developing roller shaft 32 to rotate the developing roller body 31
together with the developing roller shaft 32.
Incidentally, the developing roller shaft 32 may not penetrate the
developing roller body 31 in the first direction. For example, two
developing roller shafts 32 may extend in the first direction from
both ends in the first direction of the developing roller body 31,
respectively.
As illustrated in FIGS. 6 and 7, the developing cartridge 1
includes a gear portion 40. The gear portion 40 is positioned at
the first outer surface 11 of the casing 10. The gear portion 40
includes the developing roller gear described above, a coupling 41,
and a gear cover 43.
The coupling 41 is a rotary member configured to receive a driving
force supplied from a power source of the image forming apparatus
100. The coupling 41 is rotatable about a rotational axis extending
in the first direction. The coupling 41 has a fixing hole 411
recessed in the first direction. Upon attachment of the drum
cartridge 2 to which the developing cartridges 1 are attached to
the main body portion 9 of the image forming apparatus 100, a
transmission shaft (not illustrated) of the main body portion 9 is
inserted into the fixing hole 411. As a result, the transmission
shaft and the coupling 41 are coupled to each other so as not to
rotate relative to each other. Accordingly, rotation of the
transmission shaft causes rotation of the coupling 41, which causes
rotation of the developing roller gear along with the rotation of
the developing roller 30. Further, rotation of the coupling 41 also
causes rotations of a supply roller (not illustrated) and an
agitator (not illustrated).
The casing 10 has an outer surface positioned at another end
portion in the third direction of the casing 10. A handle 38 is
positioned at the outer surface to be gripped by a user.
When performing a printing process in the image forming apparatus
100, the controller 102 drives a motor (not illustrated). As the
motor is driven, the photosensitive drum 21 and the developing
roller 30 receive a driving force from the motor through the
transmission shaft and the coupling 41 to rotate. Further, the
controller 102 supplies electric power to each charger (not
illustrated) to charge the outer circumferential surface of the
corresponding photosensitive drum 21. Further, the controller 102
turns on each light source (not illustrated) so that the light
source emits light onto the outer circumferential surface of the
corresponding photosensitive drum 21. Accordingly, an electrostatic
latent image corresponding to an image to be printed is formed on
the outer circumferential surface of the photosensitive drum
21.
The toner accommodated in the developing cartridge 1 is supplied
through the developing roller 30 to the electrostatic latent image
formed on the photosensitive drum 21. As a result, the
electrostatic latent image becomes a visible toner image on the
outer circumferential surface of the photosensitive drum 21. In the
meantime, a printing sheet is conveyed to a portion between the
photosensitive drum 21 and the transfer belt. Hence, the toner
image is transferred from the outer circumferential surface of the
photosensitive drum 21 to the printing sheet. The printing sheet
carrying the toner image thereon is then conveyed to a fixing unit
(not illustrated) provided in the image forming apparatus 100 where
the toner image is thermally fixed to the printing sheet. As a
result, an image is printed on the printing sheet.
In the image forming apparatus 100, it is preferable that each of
the developing rollers 30 be separated from the corresponding one
of the photosensitive drums 21 in order to change colors for
printing or during a standby period. To this end, the image forming
apparatus 100 according to the present embodiment provides a
contacting state and separated state. In the contacting state of
the image forming apparatus 100, the developing rollers 30 and the
corresponding photosensitive drums 21 are in contact with each
other in a state where the developing cartridges 1 are attached to
the drum cartridge 2. In the separated state of the image forming
apparatus 100, the developing rollers 30 and the corresponding
photosensitive drums 21 are separated from each other in the state
where the developing cartridges 1 are attached the drum cartridge
2.
To this effect, as components for realizing the contact and the
separation between the developing rollers 30 and the corresponding
photosensitive drums 21, each of the developing cartridges 1
further includes a first cam 61, a second cam 62, a connection
member 63, two hooks 64, a first guide groove 65, a second guide
groove 66, two positioning grooves 67, and an elastic member 68.
Also, as components for realizing the contact and the separation,
the drum cartridge 2 further includes first cylinders 24 and second
cylinders 25. Still also, as components for realizing the contact
and the separation, the main body portion 9 includes drive shafts
103.
<2. Components in Drum Cartridge for Performing Contact and
Separation>
Hereinafter, components of the drum cartridge 2 for performing the
contact and the separation between the developing rollers 30 and
the corresponding photosensitive drums 21 will be described with
reference to FIGS. 2 to 4. FIG. 3 is a perspective view of the
first cylinder 24. FIG. 4 is a perspective view of the second
cylinder 25.
As illustrated in FIG. 2, in a state where the developing
cartridges 1 are attached to the drum cartridge 2, the first outer
surfaces 11 of the developing cartridges 1 face an inner surface of
the side frame 201 in the first direction. Similarly, in a state
where the developing cartridges 1 are attached to the drum
cartridge 2, the second outer surfaces 12 of the developing
cartridges 1 face an inner surface of the side frame 202 in the
first direction.
As indicated by a broken line in a partial enlarged view in FIG. 2,
the side frame 201 includes the first cylinders 24. That is, the
first cylinders 24 are positioned at one end portion in the first
direction of the frame 200.
FIG. 3 is an exploded perspective view of the first cylinder 24 and
a bearing 26 that holds the first cylinder 24. As illustrated in
FIG. 3, the first cylinder 24 is cylindrical in shape centered on a
first rotational axis extending in the third direction. The first
cylinder 24 has an outer circumferential surface serving as a first
contact surface 240 that is capable of contacting a first inclined
surface 61c of the first cam 61 (described later). The first
cylinder 24 has one end portion and another end portion in the
third direction each rotatably supported by the bearing 26. With
this configuration, the first cylinder 24 is rotatable about the
first rotational axis extending in the third direction.
As indicated by a broken line in another partial enlarged view in
FIG. 2, the side frame 202 includes the second cylinders 25. That
is, the second cylinders 25 are positioned at another end portion
in the first direction of the frame 200.
FIG. 4 is an exploded perspective view of the second cylinder 25
and a bearing 27 that holds the second cylinder 25. As illustrated
in FIG. 4, the second cylinder 25 is cylindrical in shape centered
on a second rotational axis extending in the third direction. The
second cylinder 25 has an outer circumferential surface functioning
as a second contact surface 250 capable of contacting a second
inclined surface 62c of the second cam 62 (described later). The
second cylinder 25 has one end portion and another end portion in
the third direction each rotatably supported by the bearing 27.
Thus, the second cylinder 25 is rotatable about the second
rotational axis extending in the third direction.
Each of the first cylinders 24 and corresponding each of the second
cylinder 25 are aligned with each other in the first direction as a
pair. As will be described later, components in the developing
cartridge 1 for performing the contact and the separation between
the developing rollers 30 and the corresponding photosensitive
drums 21 are capable of contacting the first contact surface 240 of
the first cylinder 24 and the second contact surface 250 of the
second cylinder 25.
<3. Components in Main Body Portion for Performing Contact and
Separation>
Hereinafter, components of the main body portion 9 for performing
the contact and the separation between the developing rollers 30
and the corresponding photosensitive drums 21 will be described.
The main body portion 9 includes the drive shafts 103 as
illustrated in FIGS. 12, 13, 15 and 16. Each of the drive shafts
103 has one of a solid cylindrical shape and solid prismatic
columnar shape extending in the first direction. Each of the drive
shafts 103 is movable in the first direction between an advanced
position and a retracted position upon receiving a driving force
from a power source of the main body portion 9.
<4. Components in Developing Cartridges for Performing Contact
and Separation>
Next, components of the developing cartridges 1 for realizing the
contact and the separation between the developing rollers 30 and
the corresponding photosensitive drums 21 will be described with
reference to FIGS. 5 through 10. FIG. 8 is a perspective view of
the first cam 61, the second cam 62, and the connection member 63.
FIG. 9 is a perspective view of the developing cartridge 1 in which
the connection member 63 has been removed. FIG. 10 is a view
particularly illustrating a portion in the vicinity of a retainer
61e of the first cam 61.
As illustrated in FIGS. 5 through 7, the first cam 61 is positioned
at the one end portion 91 of the casing 10 and positioned at the
third outer surface 13 of the casing 10. The first cam 61 includes
a first end 61a, and a second end 61b positioned closer to the
other end portion 92 of the casing 10 in the first direction than
the first end 61a is to the other end portion 92.
The first cam 61 further has the first inclined surface 61c
inclined so as to be distant from the casing 10 as extending from
the second end 61b toward the first end 61a. In other words, the
first inclined surface 61c approaches the casing 10 in the second
direction as extending in the first direction from one side toward
another side of the casing 10. In the state where each developing
cartridge 1 is attached to the drum cartridge 2, the first cam 61
is movable relative to the photosensitive drum 21 in the second
direction together with the casing 10 and the developing roller 30.
Further, as will be described later in detail, the first cam 61 is
movable in the first direction relative to the casing 10 and the
developing roller 30 between a first position and a second
position. The first cam 61 in the second position is positioned
closer to the other end portion 92 than the first cam 61 in the
first position is to the other end portion 92.
The first guide groove 65 is positioned at the third outer surface
13 of the casing 10. Specifically, the lid 10B has the first guide
groove 65 at one end portion in the first direction thereof. The
first guide groove 65 extends in the first direction and is
recessed from an outer surface of the lid 10B toward another end
portion in the second direction of the lid 10B. With this
configuration, the first guide groove 65 can guide movement of the
first cam 61 between the first position and the second
position.
As illustrated in FIGS. 6 and 7, the first end 61a has a pressure
contact surface 61d. The pressure contact surface 61d is a surface
that extends perpendicularly to the first direction.
As illustrated in FIGS. 5 and 6, the second cam 62 is positioned at
the other end portion 92 of the casing 10 and positioned at the
third outer surface 13 of the casing 10. The second cam 62 includes
a third end 62a, and a fourth end 62b positioned closer to the
other end portion 92 of the casing 10 in the first direction than
the third end 62a is to the other end portion 92.
The second cam 62 has the second inclined surface 62c inclined so
as to be distant from the casing 10 as extending from the fourth
end 62b toward the third end 62a. In other words, the second
inclined surface 62c approaches the casing 10 in the second
direction as extending in the first direction from the one side
toward the other side of the casing 10. In the state where the
developing cartridge 1 is attached to the drum cartridge 2, the
second cam 62 is movable relative to the photosensitive drum 21 in
the second direction together the casing 10 and the developing
roller 30. In addition, the second cam 62 is movable in the first
direction relative to the casing 10 and the developing roller 30
between a third position and a fourth position. The second cam 62
in the fourth position is positioned closer to the other end
portion 92 than the second cam 62 in the third position is to the
other end portion 92.
The second guide groove 66 is positioned at the third outer surface
13 of the casing 10. Specifically, the lid 10B has the second guide
groove 66 at another end portion in the first direction thereof.
The second guide groove 66 extends in the first direction and is
recessed from the outer surface of the lid 10B toward the other end
portion in the second direction of the lid 10B. Hence, the second
guide groove 66 can guide movement of the second cam 62 between the
third position and the fourth position.
In the present embodiment, the connection member 63 is a sheet-like
member formed of material having flexibility such as polyethylene
terephthalate resin. In the following description, a region between
one end and another end of the connection member 63 will
occasionally be referred to as "intermediate portion of the
connection member 63".
The connection member 63 connects the first cam 61 and the second
cam 62 to each other. Specifically, the connection member 63
connects the first end 61a of the first cam 61 and the fourth end
62b of the second cam 62 to each other through the hooks 64. More
specifically, one end of the connection member 63 is connected to
the first end 61a of the first cam 61 through one of the hooks 64,
and another end of the connection member 63 is connected to the
fourth end 62b of the second cam 62 through the remaining one of
the hooks 64.
The connection member 63 has a portion extending in the first
direction and is positioned at the fourth outer surface 14 of the
casing 10. In other words, the portion of the connection member 63
extends in the first direction along the fourth outer surface 14.
With this arrangement, a sufficient distance from the one end to
the other end of the connection member 63 can be obtained. Further,
the connection member 63 can have at least two bending portions. In
other words, the intermediate portion of the connection member 63
has a portion extending in the first direction, and another portion
extending in a direction crossing the first direction.
As illustrated in FIGS. 7 and 9, the two positioning grooves 67 are
positioned at the fourth outer surface 14 of the casing 10 with an
interval therebetween in the first direction. In the present
embodiment, each of the positioning grooves 67 includes a pair of
groove walls 671 extending in the first direction and protruding
from the fourth outer surface 14 in the second direction. At least
a portion of the connection member 63 is positioned within the
positioning grooves 67 (i.e., between the pair of groove walls 671
of each positioning groove 67). This configuration can prevent the
intermediate position of the connection member 63 from deviating in
position in the third direction on the fourth outer surface 14. The
two positioning grooves 67 are an example of a groove.
As illustrated in FIGS. 5, 6 and 11, the elastic member 68 is a
tension coil spring in the present embodiment. The elastic member
68 is positioned at the other end portion 92 of the casing 10 and
positioned at the third outer surface 13. The elastic member 68 has
one end connected to the second cam 62, and another end connected
to the third outer surface 13 of the casing 10. The elastic member
68 urges the second cam 62 in a direction from the fourth position
toward the third position.
As illustrated in FIG. 10, the first cam 61 includes the retainer
61e for preventing the first cam 61 from disengaging from the first
guide groove 65. The retainer 61e protrudes from a body of the
first cam 61 in the third direction from one side toward another
side. The gear cover 43 has a notch 43a on a wall surface (side
surface) at one end portion thereof in the second direction. The
notch 43a is open toward the other side in the first direction of
the casing 10. As illustrated in FIG. 10, the retainer 61e of the
first cam 61 is capable of contacting an inner edge of the notch
43a. By this contact, further movement of the first cam 61 in the
first direction from the other side toward the one side can be
restrained. In other words, disengagement of the first cam 61 from
the first guide groove 65 can be avoided by the contact between the
retainer 61e and the inner edge of the notch 43a.
<5. Movement of Each Component at the Time of Switching Between
Contacting State and Separated State>
Hereinafter, how each component operates for realizing switching
between the contact and the separation will be described with
reference to FIGS. 11 through 16.
FIG. 11 is a view of the developing cartridge 1 and the
photosensitive drum 21 in the contacting state of the image forming
apparatus 100 as viewed in the first direction from the other side
toward the one side. FIG. 12 is a view of the developing cartridge
1 in the contacting state of the image forming apparatus 100 as
viewed in the third direction from the other side toward the one
side. FIG. 13 is a perspective view of the developing cartridge 1
and the photosensitive drum 21 in the contacting state of the image
forming apparatus 100. FIG. 14 is a view of the developing
cartridge 1 and the photosensitive drum 21 in the separated state
of the image forming apparatus 100 as viewed in the first direction
from the other side toward the one side. FIG. 15 is a view of the
developing cartridge 1 in the separated state of the image forming
apparatus 100 as viewed in the third direction from the other side
toward the one side. FIG. 16 is a perspective view of the
developing cartridge 1 and the photosensitive drum 21 in the
separated state of the image forming apparatus 100.
In the image forming apparatus 100, when the drive shaft 103 is
driven to move toward the advanced position from the one side
toward the other side in the first direction of the casing 10, the
pressure contact surface 61d of the first cam 61 is pressed by the
drive shaft 103. In accordance with application of the pressing
force by the drive shaft 103, the first cam 61 moves from the first
position to the second position within the first guide groove 65.
As the first cam 61 moves to its second position, a tensile force
of the connection member 63 becomes greater than a tensile force of
the connection member 63 in the first position of the first cam 61.
When the tensile force of the connection member 63 becomes greater
than the urging force of the elastic member 68, the fourth end 62b
of the second cam 62 is pulled by the connection member 63, whereby
the second cam 62 moves from the third position to the fourth
position within the second guide groove 66.
The first inclined surface 61c is in contact with the first contact
surface 240 of the first cylinder 24. Here, a contacting position
of the first inclined surface 61c with respect to the first contact
surface 240 is gradually shifted from a position close to the
second end 61b (see FIG. 12) to a position close to the first end
61a (see FIG. 15). As a result, a distance in the second direction
between the casing 10 and the first contact surface 240 of the
first cylinder 24 gradually increases. A pressing force applied to
the first inclined surface 61c by the first contact surface 240 of
the first cylinder 24 causes the casing 10 and the developing
roller 30 to move away from the photosensitive drum 21.
Similarly, the second inclined surface 62c is in contact with the
second contact surface 250 of the second cylinder 25. Here, a
contacting position of the second inclined surface 62c with respect
to the second contact surface 250 is gradually shifted from a
position close to the fourth end 62b (see FIG. 12) to a position
close to the third end 62a (see FIG. 15). As a result, a distance
in the second direction between the casing 10 and the second
contact surface 250 of the second cylinder 25 gradually increases.
In this way, the casing 10 and the developing roller 30 move away
from the photosensitive drum 21 since the second inclined surface
62c is applied with a pressing force by the second contact surface
250 of the second cylinder 25.
As described above, both end portions in the first direction of the
casing 10 (i.e., the first inclined surface 61c and the second
inclined surface 62c) are respectively pressed by the first contact
surface 240 of the first cylinder 24 and the second contact surface
250 of the second cylinder 25 those are spaced away from each other
in the first direction. This configuration can accurately move the
casing 10 and the developing roller 30 away from the photosensitive
drum 21 while avoiding inclination of the casing 10 relative to the
first direction.
On the other hand, when the drive shaft 103 is driven to move
toward its retracted position from the other side to the one side
in the first direction of the casing 10, the second cam 62 moves
back from the fourth position to the third position within the
second guide groove 66 because the urging force of the elastic
member 68 becomes greater than the tensile force of the connection
member 63. Further, the first cam 61 also moves back from the
second position to the first position within the first guide groove
65 because the first end 61a of the first cam 61 is pulled by the
connection member 63. At this time, disengagement of the first cam
61 from the first guide groove 65 can be prevented due to the
contact of the retainer 61e of the first cam 61 with the inner edge
of the notch 43a.
In the meantime, the frame 200 of the drum cartridge 2 further
includes an urging mechanism (not illustrated) for urging the
casing 10 toward the photosensitive drum 21. The urging mechanism
urges the developing cartridge 1 in the second direction from the
other side toward the one side, whereby the developing roller 30
and the photosensitive drum 21 are again brought into contact with
each other. As such, switching between the contacting state (see
FIGS. 11 through 13) and the separated state (see FIGS. 14 through
16) can be realized in the image forming apparatus 100.
<6. Summary>
As described above, the developing cartridge 1 according to the
present embodiment includes the casing 10, the developing roller
30, the first cam 61, the second cam 62, and the connection member
63. The second cam 62 moves from the third position to the fourth
position in accordance with the movement of the first cam 61 from
the first position to the second position due to the tensile force
of the connection member 63. During the movement, the first cam 61
and the second cam 62 are respectively pressed by the arcuate
surfaces (the first and second contact surfaces 240 and 250) of the
drum cartridge 2, thereby separating the developing roller 30 from
the photosensitive drum 21.
As such, in the developing cartridge 1 according to the present
embodiment, the separation of the developing roller 30 from the
photosensitive drum 21 can be performed by the driving force
applied only to the one side in the first direction of the
developing cartridge 1. Application of a driving force to both
sides in the first direction of the developing cartridge 1 is
unnecessary.
Further, in the developing cartridge 1 according to the present
embodiment, the first cam 61 and the second cam 62 are positioned
at the third outer surface 13 of the casing 10. In addition, at
least a portion of the connection member 63 extends in the first
direction along the fourth outer surface 14 of the casing 10. With
this configuration, a sufficient length from the one end to the
other end of the connection member 63 can be obtained, and at least
two bending portions can be provided in the connection member 63.
As a result, a tensile force can be generated in the connection
member 63 with high accuracy.
Further, in the developing cartridge 1 according to the present
embodiment, the first cam 61 has the first inclined surface 61c,
and the second cam 62 has the second inclined surface 62c. With
this configuration, the first cam 61 and the second cam 62 can be
accurately pressed by the first contact surface 240 and the second
contact surface 250 of the drum cartridge 2, respectively, while
suppressing inclination of the developing cartridge 1.
Further, the developing cartridge 1 according to the present
embodiment includes the elastic member 68. Hence, when a tensile
force of the connection member 63 decreases after the second cam 62
is pulled from the third position to the fourth position due to the
tensile force of the connection member 63, the second cam 62 can
move back from the fourth position to the third position owing to
the urging force of the elastic member 68. As a result, the
developing roller 30 once moved away from the photosensitive drum
21 can be easily returned to its original position (i.e., the
position where the developing roller 30 is in contact with the
photosensitive drum 21).
Further, in the developing cartridge 1 according to the present
embodiment, the casing 10 has the two positioning grooves 67. At
least a portion of the intermediate position of the connection
member 63 is positioned within each of the positioning grooves 67.
With this configuration, the positioning grooves 67 can restrain at
least the portion of the intermediate portion of the connection
member 63 from displacing in the third direction.
Further, the casing 10 of the developing cartridge 1 according to
the present embodiment includes the lid 10B. The lid 10B has the
first guide groove 65 and the second guide groove 66. Since the lid
10B is a flat plate like member, the first guide groove 65 and the
second guide groove 66 can be easily formed in the lid 10B.
Further, in the developing cartridge 1 according to the present
embodiment, the first cam 61 includes the retainer 61e. This
retainer 61e can restrain disengagement of the first cam 61 from
the first guide groove 65 due to the application of tensile force
by the connection member 63.
Further, in the developing cartridge 1 according to the present
embodiment, the first end 61a of the first cam 61 has the pressure
contact surface 61d. The first cam 61 moves from the first position
to the second position when the pressure contact surface 61d
receives a pressing force. That is, owing to the pressure contact
surface 61d, the first cam 61 can move from the first position to
the second position. Simultaneously, the second cam 62 can move
from the third position to the fourth position by the tensile force
of the connection member 63 in accordance with movement of the
first cam 61 from the first position to the second position.
Further, the main body portion 9 includes the drive shaft 103 in
the present embodiment. In the case where the drive shaft 103
applies a pressing force to the pressure contact surface 61d of the
first cam 61, the first cam 61 moves from the first position to the
second position, and the second cam 62 moves from the third
position to the fourth position due to the tensile force of the
connection member 63. Hence, the developing roller 30 can separate
from the photosensitive drum 21 by the driving force received from
the main body portion 9.
Further, in the present embodiment, the drum cartridge 2 has the
first contact surface 240 and the second contact surface 250. In
the state where the developing cartridge 1 is attached to the drum
cartridge, the first contact surface 240 is in contact with the
first inclined surface 61c, and the second contact surface 250 is
in contact with the second inclined surface 62c. Accordingly, the
first cam 61 moves in the first direction from the one side toward
the other side while in contact with the first contact surface 240,
and the second cam 62 also moves in the first direction from the
one side toward the other side while in contact with the second
contact surface 250.
With this configuration, the first inclined surface 61c is pressed
by the first contact surface 240 and the second inclined surface
62c is pressed by the second contact surface 250, thereby causing
the casing 10 and the developing roller 30 to move from a
contacting state where the developing roller 30 is in contact with
the photosensitive drum 21 to a separated state where the
developing roller 30 is separated from the photosensitive drum 21.
Also, this configuration can restrain the casing 10 and the
developing roller 30 from being inclined relative to the first
direction.
Further, the first cylinder 24 is rotatable about the first
rotational axis, and the second cylinder 25 is rotatable about the
second rotational axis in the present embodiment. Accordingly, a
frictional force generated between the first inclined surface 61c
and the first contact surface 240, and a frictional force generated
between the second inclined surface 62c and the second contact
surface 250 can be reduced in the case where the first cam 61 and
the second cam 62 move in the first direction toward from the one
side toward the other side in a state where the first contact
surface 240 is in contact with the first inclined surface 61c and
the second contact surface 250 is in contact with the second
inclined surface 62c.
<7. Modifications>
While the description has been made in detail with reference to the
specific embodiment, it would be apparent to those skilled in the
art that various modifications can be made thereto.
In the above-described embodiment, at least a portion of the
connection member 63 extends in the first direction on the fourth
outer surface 14 of the casing 10. Instead of the above
configuration, at least a portion of the connection member 63 may
extend in the first direction on the outer surface of the casing 10
where the handle 38 is positioned. That is, it is preferable that
the connection member 63 has a portion that extends in the first
direction on an outer surface of the casing 10 different from the
third outer surface 13.
While only the first cam 61 has the retainer 61e in the
above-described embodiment, not only the first cam 61 but also the
second cam 62 may have a retainer.
In the above-described embodiment, the connection member 63 is a
sheet-like member. However, the connection member 63 may be a wire
member. Further, the connection member 63 is formed of resin in the
above-described embodiment. However, instead of resin, the
connection member 63 may be formed of metal (such as leaf
spring).
In the above-described embodiment, two of the positioning grooves
67 are spaced away from each other in the first direction on the
fourth outer surface 14 of the casing 10. However, one positioning
groove 67 may be positioned to extend over an entire region of the
casing 10 from the one end portion 91 to the other end portion 92
in the first direction.
Further, the detailed configuration and the shape of the developing
cartridge may be suitably modified without departing from the scope
of the present disclosure. Further, each component in the
above-described embodiment and the above modifications may be
suitably combined together avoiding conflicting combination.
* * * * *